Pressure actuated punching mechanism



' Nov. 14, 1933. D. w. HART 1,935,397

PRESSURE ACTUATED PUNCHING MECHANISM Filed July 16, 1931 b i UM j a & ggw H15 ATTORNEY.

to the article being punched. I

' refer to similar parts, 7

Patented Nov. 14, 1933 .1.

,PRESSURE A TUATED PUNCHING MECHANISM I -Dudley W. Hart, Phillipsburg,N.-J., assignor to Ingersoll-Band Company, Jersey City, N. .L, acorporation of New Jersey I Application July 16, 1931. Serial'No.551,165

2-Claims.' (01. 765) This invention relates to punching mechanism,modate a reciprocatory hammer piston Q. The but more particularly to apunching mechanism hammer piston Q may, be of a well known type adaptedfor pinning out theends of hollow bores. having a head R slidable in theenlarged portion of working implements, such as drill steelswand O ofthe piston chamber, and a rearward exten-- i the like, and in which thebore or portions there-, sion S which is guided by the reduced portion Poflhave become deformed during prior forging of the piston chamber.operations. 7 In mechanisms employing pistons of the type One object ofthe invention is to effect such described the extensions may serve as ameans pinning out or punching of drill steels through for controllingthe distribution of pressure fluid 1 3" the application of indirectblows delivered to, the to the various portions of the piston chamber Lpunching mechanism and transmitted thereby to for actuating the pistonQ. The extension S is the punch .pin. 1 h v p accordingly provided withan annular groove T Another object is to effect the Withdrawal of nearthe point of union of said extension and the the punch pin from thedrill steel by indirect head R to establish communication between the15'. blows of the hammer piston applied tothe punchrear end of theenlarged portion 0 and a supply ing mechanism, and another object is tovprovide passage U leading from the rear end of the rea punchingmechanism with, arresting meansduced portion P of the piston chamber toa point; adapted to render alternate blows of. the hammer in saidreduced portion slightlyrearwardly of piston ineifective to move thecasing with respect the rear end of theenlarged portion 0 of the pistonchamber. f Other objects willbe in part obvious and'in The neck orgroove T is of such extent that part pointed out hereinafter.whenthepiston Q pp hes its rearmost lim- In the drawing accompanyingthis specificar, fi g P iQ l in the P s on chamber the groove tion andin which similar reference characters T will establish communicationbetween the pasi, sage U and the rear end of the enlarged portion Figure1 is a longitudinal sectional elevation O ofthe piston chamber. v e p v,Y of a punching mechanism constructed in accord- The pressure fluid thusdistributed may be inance withthe practice'of the invention, and.troduced directlyinto the rear end of the reduced "Figure 2 is atransverse view taken through portion P which. will therefore act'as aconstant 301 Figure 1 on the line 22 looking in the direction pressurechamber. and in consequence of which indicated by the arrows. r p p therear end V of the extension S will be con- ,Referring more particularlyto the drawing, stantly exposed-to pressure fluid tending to acthepunching mechanismconstructed in accordtuate the piston Q forwardly.

ance with the practice of the inventionand des The admission ofpressurefluid to the front 35 ignatedgenerally by A is mountedupona-supend of the piston chamber L is likewise controlled port Bcomprising a bracket C which may be by the extension S. Such pressurefluid'is con- 7 suitably secured to a clamping deviceDvof a well veyedtothis end ofv the piston chamber by an known type. The clamping device Dmay, as is inlet'passage W having its inlet port' X located customary,consist of a base memberE and a intermediate the ends of the reducedportion P 40 clamping die F movable relatively ;-to the base of thepiston chamber. Thus arranged the inert i member E and, cooperatingtherewith toclamp port X will be uncovered by the rear end of thethework, suchas a drill steel G, securely in poextension S as the pistonapproaches its forward sition. 1 v v limiting position to admitpressurefiuid into the Qn the outer or free endof the bracket Cis a front end ofthe enlarged portion 0 of the piston vertical extension H which supportsone end of chamber.

guide rods J whereon the; punching mechanism The outlet portY of theinlet passage W pref- A isslidably mounted. The opposite ends of theerably opens into the enlarged portion 0 of the guide rods J maybeconvenientlythreadedinto piston chamber at a point located'som'ewhatthebase member E and said guide rods lie inthe rearwardly: of theextreme 'front vend of, said 50 same transverse plane and are parallelwith re-; enlarged portion 0 so that, during the operation spect toeachother. V f of the punching mechanism,- the piston willat Thepunching mechanism A comprises a cylinall/timesbeprevented from striking,a direct der K bored to form a piston chamberL which blow-against afront head 2 which forms a c10- consists in this instance of anenlargedportion sure for the frontend of thepiston chamber L.v

. O and a rearward r educed portion B to accom- In other words, thesupply and inlet passages and the elements whereby they are controlledare so arranged that during both the forward and rearward stroke of thepiston the end of the piston chamber toward which the piston Q is movingwill be charged with pressure fiuid to assure prompt reversal of thepiston before said piston may come into contact with the closures forthe ends of the piston chamber, as for instance, the front head Z and aback head I) which seals the rear end of the reduced portion P of thepiston chamber.

In accordance with a well understood practice, in apparatus employingpistons of the character described, pressure fluid utilized foractuating the piston is exhausted only from the enlarged portion 0 ofthe piston chamber. The cylinder K is accordingly provided with anexhaust port 0 located intermediate the ends of the enlarged portion 0and controlled by the head R of the piston Q.

Preferably the cylinder K is provided with a pair of lugs d located nearthe extremities of said cylinder and having bores etherein to receivethe guide rods J whereby the punching mechanism A is supported withrespect to the drill steel G.

The front head Z and the back head I) may be secured fixedly to thecylinder K in any suitable manner, as for instance by side rods 1arranged on opposite sides of the cylinder K and having nuts g threadedon one end thereof to clamp the p gether. 45

heads securely against the ends of the cylinder K.

In addition to serving as a closure for the front end of the pistonchamber L the front head Z also acts as a holder for the workingimplement, such as a punch pin h. To this end the front head may beprovided with a forwardly directed extension 7' having a bore to receivea'shank o of the punch pin h. The'punch pin it may be 40 secured in theextensiona' in any suitable manner, as for instance by a pin p whichextends through registering apertures in the shank o and the extension9' to lock these elements securely to- A retaining element, such as aspring q, may be disposed about the extension 7 to overlie the ends ofthe pin 10 and thus prevent endwise movement of the said pin.

As will be observed the punching mechanism A is so located with respectto the clamping elements E and F that the punch pin h will lie in theaxial plane of the drill steel G and thereforepin h is adapted to open.

' The operation of the apparatus so far described is as follows: Withthe rear end of the reduced portion P of the piston chamber open topressure fluid supply, pressure fluid flowing into W said reducedportion will act against the rear 60 end 'V of the extension S to drivethe piston Q forwardly. The pressure acting against this endof thepiston'will be assisted by pressure fluid previously admitted from thesupply passage-U through the annular groove T into the rear end of theenlarged portion 0 of the piston chamber and acting against the rear endof the head B. As the piston Q moves forwardlythe head R will uncoverthe exhaust port 0 and pressure .70 ffluid will then be exhausted fromthe rear end of the enlarged portion 0 to the atmosphe r e.

' With the piston in this position the rear end of the extension S willuncover the inlet passage W. Pressure fluid will then be admitted intothe e front end of the enlarged portion Oof the piston chamber toreverse the piston. Upon such reversal of the piston a sharp jar orindirect blow will be transmitted to the front head Z which will carrythe entire punching mechanism in the direction of the drill steel G andwill therefore drive the punch pin h into the passage r of the drillsteel.

Admission of pressure fluid into the front end of the piston chamber Lmay continue throughout a brief portion of the rearward travel of thepiston Q after which communication between the inlet passage W and thereduced portion P of the piston chamber will be cut off by the extensionS of the piston, so that only the extreme ends of the piston chamberwill be exposed to pressure fluid. Inasmuch that the front end of thehead R of the piston Q is of larger establish communication between thesupply passage U and the rear end of the enlarged portion 0 of thepiston chamber to admit pressure fluid thereinto to assist in drivingthe piston forwardly.

Upon reversal of the piston at the rearmost. limit of its travel a jaror indirect blow will of I course also be imparted to the punchingmechanism and which jar in the absence of suitable arresting deviceswould of coursetend to again withdraw the punch pin from .the drillsteel G; In order to prevent such withdrawal of the punch pin thepunching mechanism. is provided with suitable arresting means adapted toselectively. render alternate jars of the hammer piston Q' ineffectiveto disturb or alter the position of the punching mechanism A withrespect to the drill steel G. i

' The arresting means selected for illustrative purposes is like thatdisclosed in U. S. Patent-No. 1,788,034 granted to William A. Smith,Sr., January 6, 1931 in which the arrangement, briefly described,consists of a bracket, herein designated by s, and'shown as forming anintegral part of the back head b. V

The bracket s has pivotally mounted thereon a friction shoe't adapted tobe pressed'into engagement with the surface of a rod'u by pressureactuated plungers v and w. Therod'u is supand at its other end by thebase member E of the clamping device; reciprocable in cylinders 03 and yrespectively forming part of the bracket s and to which cylinders thepressure fluid may be supplied by a throttle valve'z arranged, in acasing 2 mounted in this instance upon the bracket 0.

The pressure fluid for actuating the plungers i2 and w maybe carried totheir respective cylinders by suitable flexible conduits 3 and 4 foractuatingthe friction shoet from one engaging position to another andfor holding said shoe in-such engaging positions.

For a full' description of the arresting device access may be had to theaforesaidfpatent. It may, however, be herein briefly'stated that when---The plungers o and w are friction ported atone end by the verticalextension 7 against the plunger '0 will swing the friction shoe tforwardly and thus maintain the rearward portion thereof firmly inengagement with the surface of the rod u. I

With the friction shoe t thus disposed the punching mechanism A may onlytravel in a forwardly direction, that is, in a direction toward thedrill steel G upon reversal of the piston Q in the front end of thepiston chamber, but, upon reversal of the piston in the rear end of thepiston chamber the friction shoe will, by its frictional engagement withthe rod u, prevent the punching mechanism from being shifted in arearwardly direction. It will be apparent, therefore, that only thealternate blows of the piston Q, or, in other words, those jarsresulting during the act of reversal of the piston Q in the front end ofthe piston chamber will be effective to carry the punching mechanism Aalong the support.

By maintaining the friction shoe t in the position described thepunching mechanism will be advanced in the direction of the work and thepunchpin h will therefore be rapidly driven into the drill steel. v

After the passage 1 in the drill steel G has been properly shaped orreformed the throttle valve 2 may be reversed to admit pressure fluidinto the cylinder 11/. This pressure fluid acting against the plunger 'wwill rock the friction shoe rearwardly so that the front portion of saidfriction shoe will be in engagement with the rod u.

' piston in the rear end of the piston chamber the entire punchingmechanism will be carried rearwardly along the support B.

Upon reversal of the piston in the front end of the piston chamber thefriction shoe will, by its frictional engagement with the rod u, preventany movement of the punching mechanism in the direction of the drillsteel G. The punch pin it Certain very desirable advantages flow fromthe present invention. Foremost of these is the complete absence ofdirect impact of the hammer piston against the elements associatedtherewith, as for instance, the parts comprising the casing of thepunching mechanism, and only indirect blows or cushioned jars will beimparted to such mechanism for driving the punch pin it into and out ofthe work. This is an extremely desirable feature and one that enablesthe entire punching mechanism to render service for long periods of timewithout necessitating replacements due to wear or breakage as has beenthe case in apparatus of this type heretofore.

I claim:

1. A punching mechanism comprising a casing having a working implementfixedly secured thereto, a member isolated from the working implementand reciprocable in the casing to cause longitudinal vibration thereof,supporting means for the casing, and means associated with the casingand its supporting means selectively to resist vibration in onedirection and to yield to vibration in the other direction whereby thecasing may be caused to travel along the supporting means to drive theworking implement into and withdraw it from the work.

2. A punching mechanism comprising a casing, the punching implementfixedly securedi thereto, an element in the casing isolated from thepunching implement and adapted to be reciprocated by pressure fluid tocause vibration of the casing, a support for the casing, and meansassociated with the casing and its support selectively to respond tovibratory impulses to cause forward and backward movement of the casingand the punching implement lengthwise of the

